NASA's National Space Exploration Policy calls for a return to the Moon by 2020.
Unlike Apollo, the new lunar exploration initiative is to include a robust
program of science of, to, and from the Moon. Astrophysics from the Moon has
particular potential. The Moon is a unique platform for fundamental
astrophysical measurements of gravitation, the Sun, and the Universe. Lunar
laser ranging of the Earth-Moon distance provides extremely high precision
constraints on General Relativity (GR) and alternative models of gravity.
Current alternate theories for gravity, including those that explain dark
matter and dark energy, predict deviations from GR at a level that is
potentially within the grasp of the next generation of lunar laser
retroreflectors. Lacking a permanent ionosphere and, on the lunar farside,
shielded from terrestrial radio emissions, a low frequency (<100 MHz) radio
telescope on the Moon will be an unparalleled heliospheric and astrophysical
observatory. Crucial stages in particle acceleration near the Sun can be
imaged and tracked. The evolution of the Universe during and before the
formation of the first stars (termed the "Dark Ages") can be traced for the
first time, yielding high precision cosmology constraints. I will describe both
the science and the technology of these new astrophysical observatories for the
lunar surface.